Fluid delivery device



United States Patent [72] inventors Lon J-Arp, 2,413,029 12/1946 McFarland 137/99 1221MarstomAmesJn a5 0W; 2,690,761 10/1954 Gray... 137/455X Jam m J 2,785,012 3/1957 Frcwin l37/606X [21] AppLNo. 812,556 2,852,237 9/1958 Rees 4 251/1 18X [22] Filed Mar. 26,1969 2,887,094 /1959 Krukemcicrn. 137/98X Continuation ofSer. No. 454,400, May- 10, 2,954,737 /1960 Hoover, 137/99X 1965 3,194,533 7/1965 McLay 251/122 Pmmcd Primar ExaminerWilliamF ODea [73] Assignee Said Varnum assignortosaid Arp Am; 22 Emminer oafidl zobkiw Attornvy- Henderson and Strom [54] FLUID DELIVERY DEVICE I) 10 Claims 6 rawmg Igs ABSTRACT: Thls invention relates to the respirator field, and [52] U.S.C| l37/99, includes a pair of Separate cylinders having interconnected 103/9 222/335 ,1 45-6, 137/1012 pistons, which cylinders are double-valved at each end with at [51] lnt.Cl A6Zb7/00, has! one and movable for varying the volume of fluid A617" Wm/r605! 1 1/02 discharged; which valves are operable in response to a main Field ofSearch 222/57, piston bottoming a! one nd of the main cylinder, and in 2491503341 Hull-4351 response to patient inhalation, wherein the main cylinder I03/6.7. 8,9: 128/1455. 145.6. 145.7: 222/335 dischargesafluid, upon reciprocation ofits piston,fr0m which f d it derives its power, and wherein the secondary cylinder [561 Re erences I e discharges a second fluid upon reciprocation of its piston for UNITED STATES PATENTS precise volumetric proportioning with the driving fluid for 2,203,832 6/1940 Malhurg 137/99 discharge toapatient.

5015/011 02 Su 2 5560M, 3 7 89 56 i FZu/f //vPur 5660/1/0120/0 02 99 /NPUI' r l x 69 Q FLUID DELIVERY DEVICE This is a continuation of application Ser. No. 454,400, filed on May 10, 1965 and now abandoned.

This invention relates generally to a fluid mixing apparatus, and more particularly to an apparatus for mixing any two fluids in any proportion.

It is, therefore, an object of this invention to provide a novel apparatus for mixing any two fluids in any proportion.

It is another object of this invention to provide an improved apparatus for utilizing the pressure of one fluid to effect a mixing of a predetermined quantity of the one fluid with a predetermined quantity of a second fluid.

Another object of this invention is to provide an apparatus whereby fluids contained in separate containers can be mixed to any proportion by providing interconnected piston means in said containers.

It is yet another object of this invention to provide an apparatus usable, for example, as a respirator for delivering a predetermined volume of a predetermined mixture of fluid to an infant or adult; a positive pressure, fluid driven apparatus capable of delivering the fluid at a selectable constant flow rate or at a selectable constant pressure.

Still another object of this invention is an apparatus for delivering a predetermined mixture and quantity of any two fluids comprising basically a pair of containers and a pair of interconnected pistons reciprocally movable in the containers chambers, wherein that delivered can merely be varied by changing the fluids, by varying a cylinder chamber dimension, by varying both, or by varying the rate of movement of one piston relative to the other piston.

Another object of this invention is to provide a respirator apparatus, operable as an assistor or as a controller, wherein the rate of delivering a variable volume of a fluid is selectable, and further wherein the pressure of the delivered fluid is indicated to the operator at all times.

It is another object of this invention to provide an apparatus capable of attaining the above designated objects which is extremely economical to manufacture, simple and rugged in structure, and effective in operation.

These objects and other features and advantages of this invention will become readily apparent upon reference to the following description, when taken in conjunction with the accompanying drawings, wherein:

FIG. I is a perspective view of a housing within which the fluid mixing apparatus of this invention is secured;

FIG. 2 is a schematic illustration of a generic embodiment of the fluid mixing apparatus of this invention;

FIG. 3 is a schematic illustration of a specific embodiment of the invention;

FIG. 4 is a schematic illustration, showing certain container and piston elements in cross section, of one apparatus for practicing the invention based on the embodiment of FIG. 3;

FIG. 5 is a schematic illustration of an electric circuit for controlling the FIG. 4 apparatus, and wherein the apparatus is used as a patient-triggered respirator; and

FIG. 6 is a schematic illustration of a mechanical arrangement for controlling the FIG. 3 apparatus.

Basically, the apparatus comprises one piston in one cylinder driving another piston in another cylinder, wherein both cylinders can actually be closed only at one end, with the other end closeable by the reciprocating, fluid tight fit of the piston. With at least one closed end of each cylinder double valved to permit alternate charging and discharging of a fluid, and providing a spring-return for the interconnected pistons, the driving power of a fluid in one cylinder can effect either a compression of another fluid in the other cylinder, or a discharge of a predetermined quantity of the other fluid from the other cylinder, or a mixing of the other fluid with the driving fluid in a predetermined ratio, for example.

Practical applications of the apparatus include: mixing and pressurizing fluids for delivery through various'respirators or valves to humans and animals of any age for anesthesia, therapy, resuscitation, respiration assistance, or any breathing function; pressurizing of air or other non-pressurizedgases or fluids for the first mentioned purposes; pumping and/or mixing of fluids by gases, such as water by chlorine for drinking or swimming systems, oil by gases from oil wells, blood by 0 in surgery, or any fluid when powered by pressures from internal combustion engine manifolds; mixing and/or pumping explosive or inflammable liquids or gases when conventional pumps and motors may present a spark hazard; pumping of gases by liquids in many small household applications such as tire and air mattress pumps using a garden hose and water pressure; and the inflation of childrens toys with air while watering the lawn, for example. These are a few of the many practical applications to which the apparatus of this invention can be applied.

Referring now to the drawings, in FIG. I a housing indicated generally at 10 is adapted to contain an embodiment of this invention is illustrated.

Illustrated on the housing 10 is a fluid delivery flow rate selector dial l1, and a dial 12 the setting of which controls the operation .of the apparatus as either a patient-triggered assistor for a respirator, for example, or as a controller for actuatin'ga respirator to supply a fluid at a fixed rate of delivery.

A pressure gauge 13 is provided on the face of the housing 10 forind cating at all times the pressure of the fluid for each deliverycycle thereof, and a safety valve 14 of a pop-off type is also provided on the housing face for enabling the operator to instantly adjust the maximum delivery pressure and to maintain it in working condition. A manually operable trigger 16 is provided to trigger the apparatus as described more in detailhereinafter. The mixed fluid for delivery to a patient is emitted through a coupling I7, and another coupling 18 is provided for a control fluid line to the patient's mask.

At the bottom front of the apparatus, a sensitivity control device I9 is mounted, and which is operable to adjust the operation of a trigger switch as seen hereinafter. On the rear (not shown) of the housing 10, a pair of couplings are provided for receiving into the housing 10 a first fluid and a second fluid, the purpose of which will be seen hereinafter.

Referring particularly to FIG. 2, a generic embodiment of the fluid mixing apparatus of this invention is shown comprising a first cylindrical container 21 having a pair of ends 22 and 23, with a pair of ports 24 and 26 formed in the end 22, and with a port 27 formed in the end 23. A first piston 28 is mounted within the container 21 for reciprocal sliding movement therein in a fluid tight manner, and thereby forming a pair of expansible chambers 31 and 31a, on either side of the piston 28 within the container 21. The piston 28 has a pair of opposed faces 29 and 30 which are responsive to the pressure of a fluid through port 24, for example, to move in a direction away from the port 24 and force a fluid on the other side of the piston 28 outwardly through the opposite port 27.

The end 22 is slidable within the container 21 while retaining a fluid tight seal, by means of a projection 22a which has external threads 22b thereon, and which threads engage a nut 20. The nut is affixed to an idler worm gear 20a mounted in a conventional manner for rotation in place, as by a drive worm gear 25 and crank 25a, the gear 25 also rotatable in place. By rotating the gear 25, the projection 22a is thereby moved either way, left or right as viewed in FIG. 2, thus moving the end 22 outwardly or inwardly relative to its position within the container 21.

The fluid mixing apparatus includes also a second container 32 (FIG. 2) having one end 33 closed and with the opposite end 34 open. A pair of passages 36 and 37 are formed in the closed end 33 of the second container 32; and a second piston 38 is reciprocally mounted in the second container 32, having a sliding, fluid tight fit therein. The second piston 38 forms an expansible second chamber 39 within the second container 32.

The pistons 28 and 38-are interconnected, as illustrated, by a rod 40, whereby movement of either piston is transmitted in direct ratio to the other piston. It will also be noted that the pistons 28 and 38 are located at comparable positions relative to their respective containers 21 and 32. It should be noted herein that the pistons could be connected by a lever and fulcrum arrangement interposed therebetween, whereby the movement of one piston relative to the other could be varied.

To alternately fill and discharge a pair of different fluids into and from both containers 21 and 32, simultaneously, the following system of fluid transmitting conduits or lines and valves is provided. A fluid supply line 41, for supplying, for example, 50 lb./in. of oxygen to the chamber 31a is fluidly connected to the port 24 and has a two-way valve 42 interposed therein. The valve 42 in one position permits the fluid to flow toward the container 21, and in the opposite position prevents the flow. A discharge line 43 is fluidly connected to the port 26 for discharging fluid from the chamber 31a, and also has a two-way valve 44 interposed therein, the valve 44 being identical to the valve 42.

At the other end of the container 21, a discharge line 46 is fluidly connected to the port 27, and has a one-way valve 47 mounted therein on the other side of a junction 48 of the discharge line 46 with the other discharge line 43. The valve 47 will permit fluid to flow therethrough away from the port 27; however, should a vacuum or suction pressure be effected in the chamber 31 by movement of the piston 28 to the left as illustrated in FIG. 2, whereby fluid would be transmitted through the discharge line 43, the valve 44 and into the line 46, the valve 47 would not permit fluid to flow thereby. The purpose ofthis will be seen hereinafter.

Referring to the second container 32, this container is supplied by a second fluid transmitted through a supply line 49 fluidly connected to the passage 36, the supply line 49 having a one-way valve 51 mounted therein. The valve permits fluid to flow through the line 49 into the chamber 39, but not opposite thereof. A discharge line 52 is fluidly connected to the passage 37, and also has a one-way valve 53 therein for permitting the flow offluid outwardly only of the chamber 39 and through the discharge line 52 to a junction 54 with the first container discharge line 46. Thus, at the junction 54, the second fluid discharged in a predetermined quantity from the container 32 is mixed with the first fluid discharged in a predetermined quantity from the container 21, with the mixture being then discharged through a line 56 for appropriate use.

In the operation of the FIG. 2 embodiment, assume the pistons 28 and 38 to be in their illustrated positions, with valve 42 open and valve 44 closed. Assume also the chamber 3] filled with a first fluid and the chamber 39 filled with a second fluid. Upon a supply of the first fluid, oxygen in this case, under pressure through the line 41, the impinging of this fluid upon the adjacent face 29 of the first piston 28 will result in the piston 28 moving to the right of its container 21 as viewed in FIG. 2. As the piston 28, then, moves to the right, the first fluid in the chamber 31 is forced outwardly through the opposite port 27 and the discharge line 46 through the one-way valve 47.

Due to the direct connection of the rod 40 between the piston 28 and the second piston 3 8 in the second container 32, the movement of the piston 28 is transmitted directly to cause a like movement of the piston 38. Thus, the second fluidin the chamber 39 is forced outwardly through the passage 37 and the discharge line 52 to open the one-way valve 53, thereby flowing toward the junction 54. At the junction 54, the predetermined quantity ofthe first fluid in chamber 31 and the predetermined quantity of the second fluid in chamber 39 is thereby mixed for full discharge through the line 56.

Upon both pistons 28 and 38 reaching their right-most position as viewed in FIG. 2, they are then returned to their original illustrated position by means of a coil spring 55, for example, inserted between the end 23 and the piston 28, which spring 55 is expanded as the piston 38 moves to the right as viewed in FIG. 2. Prior to the return movement, it will have been noted that due to the two-way valve 44 for the first container 21 being closed, the first fluid transmitted through line 4] for the purpose of driving the piston 28 will have remained in the now expanded chamber 310. Thus, prior to a return of the piston unit, the valve 44 will be changed to an open position with a simultaneous change of the valve 42 to a closed position. The change of positions of these two valves 42 and 44 can be effected by mechanical, or by electrical means as seen hereinafter. Thus, as the pistons return and move to the left, wherein a suction or vacuum is effected, within the now expanding chambers 31 and 39, the first fluid in the chamber 31a will be by-passed through the line 43, valve 44, the junction 48 and line 46 into the chamber 31. Simultaneously, and due again to the vacuum caused within the chamber 39, another quantity of the second fluid will be sucked through the line 49 and the valve 51 opened thereby. During this return movement of the pistons, valves 47 and 53 will be held closed. Thus, upon a full reciprocation by both pistons 28 and 38, both chambers 31 and 39 are again charged with a predetermined quantity of the' different fluids prior to another mixing stroke of the pistons. It is important to note that the power stroke of the piston 28, and thus the piston 38, is effected by the same fluid from the first container 21 which is subsequently mixed with the second fluid.

One example of a mechanical arrangement for effecting the change of positions of the valves 42 and 44 as described hereinbefore is shown in schematic in FIG. 2. For example, the movable end 22 has an insert 300 provided therein with a rod 30b slidable therethrough for engagement by the piston 28. The external end of the rod 30b is connected to a rectangular linkage 300 to which another rod 30d is adjustably connected for slidable movement through an insert 302 positioned in the container end 23.

A pair of pins 35 and 35a are secured to the linkage 30c as illustrated in FIG. 2 for operative engagement each with a rocker arm 35b which is in turn adjustably connected to one of the rotary-t'ype valves 42 and 44. Thus, upon the piston 28 moving to the right in the container 21 to the rightmost position therein, it will contact the inner end 30d of the pin 30d and move it completely to the right until the piston 28 is at its end of travel within the container 21. This causes the linkage 30c also to move to the right, thus pivoting the rocker arms 35b by means of the pins 35 and 35a, whereby the valves 42 and 44 are respectively closed and opened to the passage of fluid therethrough.

Then, upon a return of the piston 28 to its leftmost position within the container 21, it strikes the inner end of the rod 30b, which had been moved into the chamber 31a due to the linkage 30c moving to the right. The piston 28 then carries the rod 30b to the left until the piston is at its leftmost position within the container 31a, whereby the valves 42 and 44 are returned to their full line position illustrated in FIG. 2.

The position of each rocker arm 35b relative to its rotary valve 42 and 44, and the extent of the length of the rod 30d relative to the linkage 300 are adjustable so as to provide for compensating adjustments should the position of the container movable end 22 be changed as described hereinbefore.

It can be readily appreciated from the schematic in FIG. 2 that the specific embodiment of the invention illustrated therein permits variation, for example, of the size of the containers 21 and 32 to vary the ratio of the mixed first and second fluids. Furthermore, either piston 28 and 38 could be adjusted lengthwise on the rod 40 and within a respective chamber to also adjust the amount of fluid discharged from either chamber, without varying the container dimensions. And as mentioned hereinbefore, rather than having a direct proportion rod 40 interconnecting the pistons 28 and 38, other interconnecting means could be used to vary the rate of movement of one piston relative to the other. Naturally, the type of fluid may always be changed.

Another embodiment of the apparatus of this invention is illustrated in FIGS. 3-5 inclusive, with the FIG. 3 illustration being of a schematic nature. A first container 57 is provided, having ends 58 and 59, with a quartet of ports 61, 62, 63, and 64 being formed in pairs, as illustrated, in the two ends 58 and 59.

A first piston 66 is reciprocally mounted in the container 57 for a fluid-tight sliding movement therein. The piston 66 is provided with opposed faces 67 and 68, and in turn divides the container into a pair of expansible chambers 69 and 690.

A second container 71 also has a pair of closed ends 72 and 73, with a pair of passages 74 and 76 formed in one closed end 72, and another pair of separate passages 77 and 78 formed in the other closed end 73. A second piston 79 is reciprocally mounted in the container 71 for a sliding, fluid-tight fit therein.

The second piston 79 is also provided with a pair of opposed faces 81 and 82, and divides the container 71 into a pair of expansible chambers 83 and 83a. The first :nd second pistons 66 and 79 are interconnected by a straight rod 84 whereby movement of one piston, 66 for example, results in movement of the second piston 79 in direct relationship to the movement of the first piston 66. Again, means different from the rod 84 can be envisioned for varying the relative rate of movement between the two pistons 66 and 79. One example would be a lever and fulcrum arrangement.

Similarly to the FIG. 2 arrangement, the ends 58 and 72 (FIG. 6) of the containers 57 and 71 each have fluid tight sliding fits within their respective containers, being movable by a structure identical to that described in FIG. 2, and which ends 58 and 72 are movable simultaneously and a like distance due to their being interconnected by a bracket 70, the latter being connected between the projection 22a and the end 72.

A fluid transmission system for supplying and discharging fluid to and from the first container 57 includes a main fluid supply line 86 within which is interposed a main valve 85 which branches into a pair of fluid supply branches 87 and 88, and with the respective branches each having a two-way valve 89 and 91 interposed therein. The supply branch 87 is fluidly connected to the port 61, and the supply branch 88 is fluidly connected to the port 63. For discharge purposes, a pair of discharge lines 92 and 93 are fluidly connected, respectively, to the ports 62 and 64. A pair of two-way valves 94 and 96 are interposed in the lines 92 and 93, respectively, with the discharge lines joining at 97 to form a main discharge line 98.

The fluid supply and discharge system for the second container 71 includes a second fluid supply line 99 fluidly connected to the passage 74 and another second fluid supply line 101 fluidly connected to the passage 77. A pair of one-way valves 102 and 103 are interposed in the supply lines 99 and 101, respectively. The valves 102 and 103 permit fluid to flow into the container 71 but not outwardly therefrom through the supply lines 99 and 101.

For discharge purposes, another pair of lines 104 and 106 are fluidly connected to the passages 76 and 78, respectively. Another pair of one-way valves 107 and 108 are interposed in the lines 104 and 106, and permit the flow of fluid outwardly of the container 71 but not inwardly thereof through the lines 104 and 106. The lines 104 and 106 converge at 109 and by means of line 111 form a main discharge conduit 112 with the discharge line 98 of the first container 57.

With respect to the operation of the specific embodiment of the apparatus of this invention shown in FIG. 3, it may be assumed that a first fluid fills the chamber 69 and a second fluid fills the chamber 83. Furthermore, the two-way valves 89 and 96 are open to the first container 57, but the valves 91 and 94 are closed.

Upon the supply ofa first fluid, such as 50 lb./in. of oxygen through the line 86, due to the valve 85 being opened the first fluid will then pass through the line 87 and the port 61 to impinge against the face 67 ofthe first piston 66. The fluid under pressure will thus force the piston 66 to the right as illustrated, and in so doing will force a predetermined volume or charge ofthe first fluid in the chamber 69 outwardly through the open port 64, line 93, and valve 96 to the discharge line 98 for the first container 57. H

In the second container 71, due to the direct connection of the piston 79 with the piston 66, movement of the piston 79 causes a predetermined volume or charge of the second fluid in the chamber 83 to pass outwardly through the open passage 78, and the line 106 and valve 108 to the discharge line 111 for the second container 71. Thus, in the main discharge line 112, a predetermined amount of fluid from the container 57 will be mixed with a predetermined amount of fluid from the container 71, for discharge as a mixture for an appropriate use.

At the end of the stroke of the pistons 66 and 79, the expansible chamber 690 contains a like predetermined charge of the first fluid, and the expansible chamber 83a a like predetermined charge of the second fluid due to flow of the same through the line 99. This latter flow can be induced by the vacuum created in the chamber 83a as the piston 79 is moved from left to right (FIG. 3), or by the second fluid being under .its own pressure as the case may be. Due to an automatic mechanism as explained hereinafter in detail, or due to other envisionable devices, upon the pistons reaching their limit, the main valve is closed, the valves 89 and 96 closed, and the valves 91 and 94 opened.

, Then, upon an opening of the main valve 85, a supply of the first fluid through lines 86 and 88 forces the fluid to impinge against the face 68 of the piston 66, resulting in the piston moving to the left as illustrated. The first fluid is thus forced out of the chamber 69a and through the lines 92 and 98 toward line 11]. Within the second container 71, movement of the piston 79 to the left discharges the second fluid through the line 104, valve 107,junction 109, and line 111 to the main discharge line 112 where it is combined with the first fluid, the resulting fluid mixture discharged then as a single fluid.

At the end of the stroke of the pistons 66 and 79 to the left and into the positions illustrated, the expansible chambers 69 and 83 are again filled each with a predetermined volume of its respective fluid. And the main valve 85 is closed, with the valves 89 and 96 opened and the valves 91 and 94 closed, as illustrated. The embodiment of FIG. 3 is then ready for another full cycle.

A specific linkage for operating the valves 89, 91, 94 and 96 is disclosed in FIG. 6. The movable container end 66 is provided with a rod 60 connected thereto which slidably protrudes through an insert 600 threadedly inserted into and through the projection 2211, which rod 60 is connected to a link 60!: at each end of which is connected a pair of parallel, lever arms 65 and 65a. The other ends of the arms are connected to the opposite ends of another link 70'. From a connection of the link 70, a rod 70a adjustably extends inwardly and slidably through another insert 70b which is threaded into the end 59 of the container 57, with the rod 70a extended into the chamber 69.

Each arm 65 and 65a has a pair of spaced pins 65' and 65a secured thereto, both of which extend for cooperative engagement with the rocker arm 65'' of each respective valve 89, 91, 94, and 96, shown schematically in FIG. 6 as rotary-type valves. By this arrangement, movement of the rod 70a caused by the piston 66 traveling to its rightmost position in the container 57 effects a movement of the linkage to close the valves 89 and 96 from a flow of fluid thereto, and opening valves 91 and 94 for a flow of fluid therethrough. Movement of the rod 70a to the right as viewed in FIG. 6 will also cause movement of the rod 60 such that its inner end will protrude into the chamber 69 to effect upon a return movement of the piston to its leftmost position against the container end 58 a change of position of the four valves back to their original positions as illustrated in full lines in FIG. 6.

The position of each rocker arm 65 relative to its rotary valve, and the extent of the length of the rod 70a relative to the link 70' are adjustable so as to provide for compensating adjustments should the position of the container end 58 be changed as described hereinbefore. It should be noted that the lines 87, 92, 99 and 104 leading to the movable ends 58 and 72 are necessarily of a flexible nature to accommodate such movement.

in FIGS. 4 and 5, the apparatus is illustrated as it would be adapted for use as a respirator for the delivery of a predetermined volume of a predetermined mixture of a pair of fluids. The apparatus would be interposed in an inhalation line to the patient, with the apparatus made operable by the beginning inhalation of the patient. After the inhalation, the patient would exhale through a separate exhalation line, suitable valves being provided for this purpose. Then, when the patient again inhaled, the apparatus would once more be set into operation for a complete inhalation supply.

Specifically, a cylindrical container 116 is provided with a closed end 117 within which is provided a port 119, and an open end 118. The end 118 is sealed closed by a longitudinally adjustable end panel 120 within which is formed a port 121. The panel 120 is made adjustable by being attached to a tube 122 movable axially of the container 116, and which is fluidly communicable with the interior of the container 116 by the port 121. An aperture 123 is formed in the outer end of the tube 122 for a purpose hereinafter described. Within the container 116 is mounted a first piston 124 having opposed faces 125 and 126 formed thereon, and whereby the container 116 is divided into a pair of expansible chambers 127 and 127a.

A second container 128 is also provided, which is ofa cylindrical nature and which has a closed end 129 thereof provided with a passage 131 formed therein. The other end 132 of the second container 128 is open, but has a fluid-tight panel 133 adjustably movable therein. A passage 134 is formed centrally in the panel 133, and the latter is secured at one end of an axially movable tube 136, the interior ofwhich is in fluid communication with the interior of the container 128 by means of the passage 134. An aperture 137 is formed at the outer end of the tube 136 for purposes hereinafter described.

A second piston 138 is mounted within the container 128, having a pair of faces 139 and 141 formed thereon, and whereby the container 128 is divided into a pair of expansible chambers 142 and 1420.

To connect the two pistons 124 and 138, a wire 143 is provided. Although not shown as continuous due to the connections thereof with the pistons, the wire 143 functions as being continuous. The wire is trained about a pair of adjustable pulleys 144 and 146, whereby upon movement of the wire, both pistons 124 and 138 are movable simultaneously and in direct proportion. lt will be noted that as the piston 124 moves from right to left in H0. 4, the piston 138 moves equally. but from left to right. As illustrated, therefore, both pistons are relatively located in their respective containers.

The wire 143 passes through an aperture 147 formed in the closed end 117 of the first container, through the port 121 formed in the adjustable end panel 120, and then through an otherwise closed end 148 of the tube 122. The wire 143 then is trained through an aperture 149 formed in the closed end 129' of the second container, through the passage 134 in the end panel 133, and then through an otherwise closed end 151 of the second tube 136 to complete the continuous nature thereof.

The fluid transmission system for the embodiment of FIGS. 4 and comprises a main valve 150 interposed in a driving fluid supply line 152 which branches off at 153 and 154 to a pair of stub lines 156 and 157. The latter two lines are fluidly connected, respectively, to the port 119 in the closed end 117 of the first container 116, and to the aperture 123 formed in the tube 122.

Discharge lines for the first container 116 are a pair oflines 161 and 163 leading away from the stub lines 156 and 157, and within which two-way valves 162 and 164 are interposed. It will be seen that two-way valves 158 and 159 are placed in the lines 153 and 154 between the main valve 150 and the fluid communication with the container 116.

For the second container 128, a second fluid input line 166 is provided for fluid communication with the chamber 142 via the passage 131. and within which a two-way valve 167 is mounted. Discharge for the chamber 142 is provided by a line 168 also in fluid communication with the passage 131, and within which a two-way valve 169 is mounted. The line 168 joins the discharge line 163 of the first container 116 at junction 171.

At the other end of the container 128, another second fluid input line 172 is provided, having a two-way valve 173 provided therein and which is fluidly communicable with the interior chamber 142a of the container 128 via the aperture 137 in the tube 136. A discharge line 174 is also in fluid communication with the aperture 137, and has a two-way valve 176 mounted therein, the line 174 being joined to the discharge line 161 of the first container 116 at junction 177. From the junctions 171 and 177, lines 178 and 179 join to form a mixed fluid delivery line 181 for delivering the mixed fluid as appropriately determined.

It will be noted in FIG. 4, that a flow rate selector valve 182 is interposed, along with the pressure gauge 13 and pop-off safety valve 14, in the mixed fluid delivery line 181. It has been seen as it will again hereinafter during further discussion of the FIGS. 4 and 5 embodiment, that the apparatus of this invention will perform as an assistor or as a controller for a conventional respirator, wherein a fixed volume charge of a fluid mixture is discharged or delivered to the patient for each single stroke of the interconnected pistons. The rate of the delivery is determined either by the patient or by an automatic setting.

To vary the rate of delivery, but not the amount delivered, for each charge, so to speak, the flow rate selector valve 182 is provided. This valve may be ofa needle valve type, for example, whereby to control the diameter of the line 181 at that point. Thus, whereas an amount of cc. of fluid mixture is normally delivered per second, manipulation of the dial 11 (FIG. 1) to set the valve 182 can change the rate to 100 cc. per half second, or to an actual per second delivery of 200 cc. of fluid mixture. The pressure gauge 13 is a valuable indicator enabling the operator at all times to see the pressure of the fluid being delivered to the patient, from zero at the beginning ofthe inhalation, to a maximum at the end of the inhalation.

Referring now particularly to FIG. 5, the electric circuit for operating the valves and otherwise controlling operation of the apparatus of FIG. 4 is illustrated.

At the closed end 117 of the first container 116, for example, a spring limit switch 186 is mounted, which is adapted to be actuated by engagement with the piston 124. The switch 186 is connected by a lead 187 to an Eccles-Jordan flip-flop circuit 188. At the other end of the container 116, another spring limit switch 192 is mounted, and which is also connected by lead 193 to the circuit 188v From the circuit 188, a pair of solenoids 199 and 201 are connected, which solenoids control the respective positions of the valves. Thus, for example, solenoid 199 controls valves 158, 164, 167, and 176, which valves are spring biased to a normally closed position. Upon energization of solenoid 199, all four specified valves are then opened simultaneously. Solenoid 201 is shown holding normally closed, spring biased valves 159, 162, 173, and 169 open; deenergization of the solenoid 201 resulting in closing these valves. Both solenoids 199 and 201 are electrically connected to a suitable electrical potential as shown at 204 in FIG. 5.

From leads 202 and 203 between the circuit 188 and the solenoids, a pair of parallel lines 206 and 207, each having the electrical components illustrated, lead to one side of another Eccles-Jordan flip-flop circuit 208. The other side of the circuit 208 is connected by lead 209, grounded rectifier 211, series-connected rectifier 212 and condenser 213 to a normally open switch device 214, the other side of which is grounded. The circuit 208 side of the switch 214 is also held at a suitable electrical potential through a resistor 216.

On the other side of the second Eccles-Jordan circuit 208, leads 217 and 218 connect that circuit to a pair of solenoids 219 and 221, both solenoids electrically connected to a suitable electrical potential at 222 on their other side. Solenoid 219 is operably connected to the main valve (FIG. 4) and solenoid 221 is operably connected to reset switch 214. The latter switch 214 can, for example, be a negative pressure type mechanism, operable to close at the beginning of inhalation by the patient, to whom the oxygen from the container 116 and the fluid, such as room air from container 128 is being supplied in the proper mixture. The provision of the solenoid 221 is a safety feature to ensure the proper function of the patient triggered switch 214. The control device 19 (FIG. 1) is provided to vary the pressure at which the switch 214 functions so as to vary and control the response of the apparatus to the pa tlent.

Operation of the embodiment as illustrated in FIGS. 4 and 5 is as follows. Assuming a first fluid such as oxygen to be in the chamber 127a of the first container 116, and a second fluid such as room air in the chamber 142 of container 128, and with the valves in their positions as illustrated, the apparatus is shown in one position ready for operation, except the piston 124 would normally be against the panel 120 and the piston 138 would normally be against the panel 133.

As the patient begins an inhalation function of his body, the trigger switch 214 would close. The resulting electrical pulse would cause solenoid 219 to open valve 150, when the solenoid was energized by operation of the flip-flop circuit 208. Driving fluid would then begin to flow through line 152, valve 159, branch 154 and stub branch 157, and then through the interior of the tube 122 to chamber 127 in the container 116.

This would result in the piston 124 being forced from right to left as illustrated in FIG. 4, forcing the fluid in chamber 127a outwardly through the port 119, and the lines 156 and 161, also passing through the open valve 162 to the junction 177 ofa second container line.

In the second container 128, as the piston 124 effects a like movement of the piston 138 due to the interconnecting wire 143, the piston 138 moves from left to right as illustrated in FIG. 4, thus forcing the second fluid out of the chamber 142 and through the line 168 and open valve 169 to the junction 171. Thus, in line 178 a predetermined amount of the first fluid from the first container 116 flows, whereas in line 179 a predetermined amount of the second fluid from the second container 128 flows toward the first fluid. These fluids are then combined in main discharge line 181 for appropriate transmission.

When the piston 124 reaches the end of its travel in the container 116, it contacts the spring limit switch 186, which causes the flip-flop circuit 188 to switch, thus energizing, for example, solenoid 199 while de-energizing solenoid 201. The actuation of these solenoids 199 and 201 results, respectively, in valves 158, 164, 167 and 176 opening, with the other quartet of valves 159, 162, 173, and 169 closing. Simultaneously, due to operation of the flip-flop circuit 188, the flip-flop circuit 208 receives an electrical signal from the circuit 188 which effects, for example, an energization of solenoid 221 and a tie-energization of solenoid 219. Actuation of the solenoid 221 resets the trigger switch 214 to its normally open position, and deactuation of the solenoid 219 effects a closing of the main valve 150. The patient can now exhale through a separate exhalation line and suitable one-way valves (not shown).

When the patient again inhales, the main valve 150 is again opened and the cycle is repeated, except that at this time the driving piston 124 moves from left to right, as illustrated, and the driven piston 138 moves from right to left. At the end of the travel of the piston 124, the limit switch 192 is operated to again cause a closing of the main valve 150, with an opening of the valves 159, 162, 173, and 169 along with a closing of valves 158, 164, 167, and 176. Furthermore, the'patient triggered switch 214 is again reset to its normally open position. Thus, during the completion of one mechanical cycle of the apparatus of FIGS. 4 and 5, the patient has been supplied two separate volumes of fluid for inhalation purposes.

It can of course be visualized that the flip-flop circuit 208 could be so arranged, electrically, to effect more than one patient-inhalation supply of fluid at a time, as compared to the single supply just described, prior to a resetting of the patient triggered switch 214. This would thereby inject a sigh" into the respiration cycles for the patient. And furthermore, although .the embodiments are fluid powered by the driving fluid, it is quite conceivable that the patient triggered switch could actuate means for effecting reciprocal movement of the pistons without the need of a pressurizing fluid. Thus, two unpressurized fluids can be mixed in a predetermined ratio, and delivered at a controllable rate.

Although a preferred embodiment of this invention has been described and disclosed hereinbefore, it is to be remembered that various modifications and alternate constructions may be made thereto without departing from the invention as defined in the appended claims.

We claim:

1. Respirator apparatus for delivering a fluid mixture to a patient comprising in combination:

first fluid container means;

second fluid container means;

interconnected piston means reciprocally mounted in both said first fluid container means and said second fluid container means;

fluid transmission means fluidly interconnected with said first fluid container means and said second fluid container means, for supplying simultaneously a first fluid to said first fluid container means and a second fluid to said second fluid container means:

fluid discharge means fluidly interconnected to said first fluid container means and to said second fluid container means;

valve means interposed in said fluid transmission means,

said valve means operable in one position to supply said first fluid to said first fluid container means to effect a first predetermined amount of movement of said piston means to force a predetermined volume of said first fluid from said first fluid container means and a predetermined volume of said second fluid from said second fluid container means, and to discharge said fluids together as a fluid mixture through said fluid discharge means;

said valve means operable in another position to effect an opposite movement of said piston means equal to said predetermined amount of movement to force a like predetermined volume of said first fluid from said first container means and a like predetermined volume of said second fluid from said second fluid container means, and to discharge said fluids together as a fluid mixture through said fluid discharge means; and

control means responsive to the inhalation of a patient to effect placement of said valve means in said one position, said control means responsive to the completion of said first movement of said piston means to effect placement of said valve means in said another position.

2. Apparatus for delivering a fluid mixture as defined in claim 1, and further wherein the combination comprises means interposed in said fluid discharge means for controlling the rate of discharge of said fluid mixture.

3. Apparatus for delivering a fluid mixture as defined in claim 1, and further wherein the combination comprises means interposed in said fluid discharge means for indicatin the pressure of the fluid mixture.

4. Apparatus for delivering a fluid mixture" as defined in claim 1, and further wherein the combination comprises means interposed in said fluid discharge means for adjusting the maximum pressure of the fluid mixture.

5. Apparatus for delivering a fluid mixture as defined in claim 1, wherein said first fluid container means includes a cylinder within which said piston means is disposed, said cylinder having one end of which is adjustably movable toward and away from the opposite end, thereby varying the stroke of said piston means.

6. Apparatus for delivering a fluid mixture as defined in claim 5, and further wherein said second fluid container includes a cylinder within which said piston means is disposed, said cylinder having one end of which is adjustably movable toward and away from the opposite end thereby varying the stroke of said piston means.

7. Respirator apparatus for delivering a fluid mixture to a patient having a variable lung compliance in combination:

a source of a first fluid and a second fluid both under pressure;

a first container including opposite closed ends forming a first chamber therebetween for holding said first fluid, said container having a first primary port formed in one end and a second primary port in the other end for the transmission of said first fluid therethrough, said one end having a secondary port formed therein;

a first piston mounted in said first chamber for reciprocal sliding movement from one end to the other end, said first piston having a pair of opposed faces and responsive to pressure of said first fluid through either primary port and against an adjacent face to move away from said either primary port, thus forcing said first fluid on the other side of said first piston outwardly through the said second pri mary port when said piston is moving away from said secondary port, and forcing said first fluid through said secondary port when said piston moves toward said secondary port;

a second container including opposite ends at least one of which is closed and has at least an inlet passage and an outlet passage formed therein for the transmission of said second fluid therethrough;

a second piston reciprocally mounted in said second container and having a sliding, fluid tight fit therein, said second piston forming an expansible second chamber with said second container closed end, within which said second fluid is contained;

said first primary port and said inlet passage being fluidly connected to said first and second sources of fluid respectively;

means interconnecting said pistons for transmitting movement of one piston to the other piston;

first valve means operably connected to the said first primary port to transmit said first fluid under pressure therethrough and into said first container;

second valve means operably connected to said inlet passage to transmit said second fluid therethrough into said second container;

said first piston responsive to the transmission of said first fluid through said first primary port to effect a discharge of said first fluid through said second primary port, and said second piston responsive to the corresponding movement of said first piston to effect a discharge through said outlet passage of said second fluid;

fluid transmission means including said first valve means and said second valve means, and fluidly connected to said containers for combining said discharged first and second fluids;

means for returning said pistons to their original positions, said second valve means operable to transmit another amount of said second fluid to said second chamber in response to operation of said piston returning means;

said fluid transmission means including third valve means interconnecting said secondary port and said second primary port for transferring the first fluid used to move said first piston into said first chamber on the side of said first piston opposite said secondary port; and

means interconnecting said first valve means and said third valve means for actuating said first and third valve means in response to movement of said first piston from one end of said first container to the other end thereof.

8. Apparatus for delivering a fluid mixture as defined in claim 7, and further wherein means is interposed in said fluid transmission means for controlling the rate of discharge of the combined discharged first and second fluids.

9. Apparatus for delivering a fluid mixture as defined in claim 8, and further wherein means is interposed in said fluid transmission means for indicating the pressure of the combined discharged first and second fluids.

l0. Respirator apparatus for delivering a fluid mixture to a patient having a variable lung compliance, comprising in combination:

a source of a first fluid and of a second fluid, both under pressure;

a first container including opposite closed ends forming a first chamber therebetween for holding said first fluid, said container having at least one port formed in each end for the transmission of said first fluid therethrough;

a first piston reciprocally mounted in said first chamber and having a sliding, fluid tight fit therein, said piston operable as it moves in one direction to force any of said first fluid in its path of movement outwardly through the port toward which it is moving;

a second container including opposite closed ends forming a second chamber therebetween for holding said second fluid therein, said second container having at least one passage formed in each end for the transmission of said second fluid therethrough;

a second piston reciprocally mounted in said second chamber and having a sliding, fluid tight fit therein, said second piston operable as it moves in one direction to force any of said second fluid in its path of movement outwardly through the passage toward which it is moving;

means interconnecting said pistons for transmitting movement of one piston to the other piston in a predetermined ratio;

first valve means alternately movable between either of two positions wherein in one position said first fluid is supplied through one port and discharged through the opposite port, and in the second position the first fluid is supplied through the opposite port and discharged through the one port, said discharge in either position being ofa predetermined quantity;

second valve means alternately movable between either of two positions wherein in one position said second fluid is supplied through one passage and discharged through the opposite passage, and in the second position the second fluid is supplied through the opposite passage and discharged through the one passage, said discharge in either position being ofa predetermined quantity;

control means operably connected to said first valve means and to said second valve means to place said first and second valve means alternately in each of their one positions and their second positions, and to direct fluid from the sources into said containers on common sides of said pistons in either of said positions, and to then change the positions of said first and second valve means, said control means being responsive to common movement of said pistons in their chambers in either direction therein; and

means fluidly connected to each of said valve means for combining said predetermined quantities of said discharged first and second fluids. 

